title: Stabilization of 30 S ribosomal subunits of Bacillus subtilis W168 by spermidine and magnesium ions.
abstract: An explanation for the fragility of 30 S ribosomal subunits of Bacillus subtilis has been studied. Degradation of 16 S ribosomal RNA, rather than degradation of ribosomal proteins, was found to cause the inactivation of 30 S subunits. Although RNAases were bound specifically to 30 S ribosomal subunits, the RNAases were able to function. Spermidine was found to contribute to the stabilization of 30 S ribosomal subunits by inhibiting the degradation of 16 S ribosomal RNA. A high concentration of Mg2+ also stabilized the 30 S ribosomal subunits of Bacillus subtilis. The polypeptide synthetic activity of 30 S ribosomal subunits prepared in the presence of spermidine was at least 4-times greater than that of 30 S ribosomal subunits prepared in the absence of spermidine; this activity was maintained without any loss for 3 months at -70 degrees C.
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology / Q000648:ultrastructure*; D007700:Kinetics; D008274:Magnesium; D010447:Peptide Hydrolases / Q000378:metabolism; D012335:RNA, Ribosomal / Q000032:analysis; D012260:Ribonucleases / Q000378:metabolism; D012270:Ribosomes / Q000201:enzymology / Q000648:ultrastructure*; D013095:Spermidine
chemical_list: D012335:RNA, Ribosomal; D012260:Ribonucleases; D010447:Peptide Hydrolases; D008274:Magnesium; D013095:Spermidine